Biometric analysis using multipurpose electrodes

Systems and methods for biometric analysis are described. In some embodiments, a system may include a wearable device comprising a plurality of electrodes, a gesture control processing circuit, and an ECG processing circuit. A common electrode may be configured to provide signals to both the gesture control processing circuit and the ECG processing circuit. While the system is in a gesture control state, the system may be configured to obtain first biopotential signals using at least the common electrode and convert the first biopotential signals to first biopotential data for use in gesture control. While the system is in the ECG state, the system may be configured to obtain second biopotential signals using at least the common electrode and convert the second biopotential signals to ECG data for use in analyzing a user's heart rhythms.